FFmpeg
oggparsecelt.c
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1 /*
2  * Xiph CELT parser for Ogg
3  * Copyright (c) 2011 Nicolas George
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <string.h>
23 
24 #include "libavutil/intreadwrite.h"
25 #include "avformat.h"
26 #include "internal.h"
27 #include "oggdec.h"
28 
31 };
32 
33 static int celt_header(AVFormatContext *s, int idx)
34 {
35  struct ogg *ogg = s->priv_data;
36  struct ogg_stream *os = ogg->streams + idx;
37  AVStream *st = s->streams[idx];
38  struct oggcelt_private *priv = os->private;
39  uint8_t *p = os->buf + os->pstart;
40  int ret;
41 
42  if (os->psize == 60 &&
44  /* Main header */
45 
46  uint32_t version, sample_rate, nb_channels;
47  uint32_t overlap, extra_headers;
48 
49  priv = av_malloc(sizeof(struct oggcelt_private));
50  if (!priv)
51  return AVERROR(ENOMEM);
52  ret = ff_alloc_extradata(st->codecpar, 2 * sizeof(uint32_t));
53  if (ret < 0) {
54  av_free(priv);
55  return ret;
56  }
57  version = AV_RL32(p + 28);
58  /* unused header size field skipped */
59  sample_rate = AV_RL32(p + 36);
60  nb_channels = AV_RL32(p + 40);
61  overlap = AV_RL32(p + 48);
62  /* unused bytes per packet field skipped */
63  extra_headers = AV_RL32(p + 56);
68  if (sample_rate)
69  avpriv_set_pts_info(st, 64, 1, sample_rate);
70 
71  if (os->private) {
72  av_free(priv);
73  priv = os->private;
74  }
75  os->private = priv;
76  priv->extra_headers_left = 1 + extra_headers;
77 
78  AV_WL32(st->codecpar->extradata + 0, overlap);
79  AV_WL32(st->codecpar->extradata + 4, version);
80  return 1;
81  } else if (priv && priv->extra_headers_left) {
82  /* Extra headers (vorbiscomment) */
83 
84  ff_vorbis_stream_comment(s, st, p, os->psize);
85  priv->extra_headers_left--;
86  return 1;
87  } else {
88  return 0;
89  }
90 }
91 
92 const struct ogg_codec ff_celt_codec = {
93  .magic = "CELT ",
94  .magicsize = 8,
95  .header = celt_header,
96  .nb_header = 2,
97 };
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AV_WL32
#define AV_WL32(p, v)
Definition: intreadwrite.h:426
ogg_codec::magicsize
uint8_t magicsize
Definition: oggdec.h:33
ogg_stream::buf
uint8_t * buf
Definition: oggdec.h:62
ogg
Definition: oggdec.h:102
sample_rate
sample_rate
Definition: ffmpeg_filter.c:156
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
oggcelt_private::extra_headers_left
int extra_headers_left
Definition: oggparsecelt.c:30
celt_header
static int celt_header(AVFormatContext *s, int idx)
Definition: oggparsecelt.c:33
ogg_stream::pstart
unsigned int pstart
Definition: oggdec.h:65
oggcelt_private
Definition: oggparsecelt.c:29
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
ff_celt_codec
const struct ogg_codec ff_celt_codec
Definition: oggparsecelt.c:92
AVFormatContext
Format I/O context.
Definition: avformat.h:1097
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:992
ogg::streams
struct ogg_stream * streams
Definition: oggdec.h:103
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
ogg_stream::private
void * private
Definition: oggdec.h:91
version
version
Definition: libkvazaar.c:307
ogg_stream
Definition: oggdec.h:61
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:845
avformat.h
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
oggdec.h
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:1146
ff_vorbis_stream_comment
int ff_vorbis_stream_comment(AVFormatContext *as, AVStream *st, const uint8_t *buf, int size)
Parse Vorbis comments and add metadata to an AVStream.
Definition: oggparsevorbis.c:73
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
ogg_stream::psize
unsigned int psize
Definition: oggdec.h:66
ogg_codec
Copyright (C) 2005 Michael Ahlberg, Måns Rullgård.
Definition: oggdec.h:31
ogg_codec::magic
const int8_t * magic
Definition: oggdec.h:32
AV_CODEC_ID_CELT
@ AV_CODEC_ID_CELT
Definition: codec_id.h:473
ff_alloc_extradata
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0.
Definition: utils.c:451
nb_channels
int nb_channels
Definition: channel_layout.c:81